Sohsaku Yamanouchi

Novel Use of Rituximab for Steroid-Dependent Nephrotic Syndrome in Children

Background: Though rituximab (RTX) is effective for childhood steroid-dependent nephrotic syndrome (SDNS), an established regimen does not exist. The relapses tend to occur when the peripheral blood B-cell count re-arises at 3 months upon single RTX infusion. This study was conducted to clarify whether the long-term remission of SDNS can be obtained by repeated RTX administrations. Methods: RTX was administered 4 times at 3-month intervals at 375 mg/m2/time to 5 children with SDNS. The changes in the clinical indicators were analyzed. Results: The median (range) observation period was 6.3 (0.9-8.4) years before RTX and 3.2 (1.9-3.8) years following the commencement of RTX. The changes in the clinical indicators were as follows (median and range): (1) annual number of relapses: before administration 1.4 (1.1-3.5) times/year, after administration 0.0 (0.0-0.0) times/year, and (2) median steroid dosage: before administration 0.80 (0.23-0.96) mg/kg/day, after administration 0.00 (0.00-0.00) mg/kg/day. All changes were significant at p < 0.05. Relapse occurred 3 times following the start of RTX (the period to relapse was 2.2, 1.9, and 2.3 years, respectively). No serious side effects were seen. Conclusions: Repeated RTX against SDNS in children may be a useful therapeutic option.

Pathogenesis of childhood idiopathic nephrotic syndrome: a paradigm shift from T-cells to podocytes

BackgroundNephrotic syndrome is the most common cause of kidney disease in children, but its pathogenesis remains unclear. This article reviews the novel aspects of the mechanisms underlying massive proteinuria in minimal-change disease, which is the most common form of childhood nephrotic syndrome.Data sourcesThis article integrates the findings of a PubMed database search for English language articles published in the past 40 years (from September 1974 to February 2014) using the key words “pathogenesis”, “minimal change nephrotic syndrome” or “idiopathic nephrotic syndrome”.ResultsUnknown humoral factors associated with T-cell dysfunction have been thought to play an important role in the pathogenesis of minimal-change disease. However, recent findings are changing this paradigm, i.e., visceral glomerular epithelial cells (podocytes) may be involved via expression of molecules such as CD80 and angiopoietin-like 4.ConclusionsRecent evidence suggests that minimalchange disease results from interactions between humoral factors and dysfunctional podocytes. In addition to immunosuppressant drugs that target lymphocytes, a biological agent such as an antibody against the abnormal molecule(s) expressed by podocytes may provide novel drug treatment for minimal-change disease.

A Novel Nuclear Factor κB Inhibitor, Dehydroxymethylepoxyquinomicin, Ameliorates Puromycin Aminonucleoside-Induced Nephrosis in Mice

Background/Aims: Minimal-change nephrotic syndrome (MCNS) is a kidney disease defined by selective proteinuria and hypoalbuminemia occurring in the absence of cellular glomerular infiltrates or immunoglobulin deposits. Recent observations suggest that nuclear factor κB (NF-κB) of podocyte is strongly associated with the development of proteinuria in MCNS. Dehydroxymethylepoxyquinomicin (DHMEQ) is a novel NF-κB inhibitor that potently inhibits DNA-binding activity of NF-κB, resulting in several therapeutic effects in various pathological conditions. We conducted this study to ask whether DHMEQ may ameliorate the nephrosis in mice induced by puromycin aminonucleoside (PAN), which is considered to be an animal model for MCNS. Methods/Results: Pretreatment with DHMEQ alleviated the proteinuria and reversed the serum abnormalities in mice nephrosis induced by 450 mg/kg of PAN. Increased serum interleukin-6 level in PAN-induced nephrosis was also completely suppressed by DHMEQ. Electron microscopic analyses of glo-meruli indicated that DHMEQ can inhibit the podocyte foot process effacement via blocking the translocation of podocyte NF-κB from cytoplasm to nucleus. Conclusions: These results suggest that DHMEQ can be a potential therapeutic agent for MCNS.

Urinary Biomarkers for Screening for Renal Scarring in Children with Febrile Urinary Tract Infection: Pilot Study

PURPOSE Recurrent febrile urinary tract infections during infancy cause renal scarring, which is characterized by progressive focal interstitial fibrosis and may lead to renal failure. Renal scarring can be diagnosed through scintigraphy, although it seems impractical to perform renal scintigraphy for all infants with febrile urinary tract infections. Therefore, it is important to search for a biomarker to identify the presence of renal scarring. We hypothesized that urinary biomarkers of nephropathy may increase in infants with renal scarring following febrile urinary tract infections. MATERIALS AND METHODS A total of 49 infants who underwent renal scintigraphy for febrile urinary tract infections were enrolled in the study. Several measurements were performed using urine samples, including total proteins, beta2-microglobulins, N-acetyl-β-D-glucosaminidase, neutrophil gelatinase associated lipocalin, liver-type fatty acid binding protein and angiotensinogen. Values were corrected by creatinine and compared between patients with and without renal scarring. RESULTS Among urinary biomarkers only angiotensinogen in patients with scarring (median 14.6 μg/gm creatinine) demonstrated significantly higher levels than in patients without scarring (3.6 μg/gm creatinine, p <0.001). CONCLUSIONS Urinary angiotensinogen may be useful for diagnosing the presence of renal scarring.

Close association between proteinuria and regulatory T cells in patients with idiopathic nephrotic syndrome

BackgroundIdiopathic nephrotic syndrome (INS) has been considered to be a T cell disorder. Supporting this hypothesis is the reported occurrence of remission following measles infection, which suppresses T cell function. In contrast, there has been no case report suggesting an association between influenza B virus infection and the remission of INS.Case-Diagnosis/TreatmentWe report the case of a 5-year-old boy with INS who achieved remission without steroid treatment in response to influenza B virus infection. Although he relapsed soon after remission, he was successfully treated with prednisolone. Both the induction of remission and the response to prednisolone were associated with an increase in the number of circulating regulatory T cells (Tregs), assessed as CD4+CD25+Foxp3+ cells. These results suggest that both influenza B virus infection and steroid administration increased the number of circulating Tregs, thus leading to the remission of INS.ConclusionsIn summary, our case indicates an important role for Tregs in the development of the proteinuria associated with INS and sheds light on its pathogenesis. Further studies are warranted.

A Calcium-Deficient Diet in Rat Dams during Gestation and Nursing Affects Hepatic 11β-hydroxysteroid dehydrogenase-1 Expression in the Offspring

Background Prenatal malnutrition can affect the phenotype of offspring by changing epigenetic regulation of specific genes. Several lines of evidence demonstrate that calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome. We hypothesized that pregnant female rats fed a Ca-deficient diet would have offspring with altered hepatic glucocorticoid-related gene expression and that lactation would modify these alterations. Methodology We determined the effects of Ca deficiency during pregnancy and/or lactation on hepatic 11β-hydroxysteroid dehydrogenase-1 (Hsd11b1) expression in offspring. Female Wistar rats consumed either a Ca-deficient (D: 0.008% Ca) or control (C: 0.90% Ca) diet ad libitum from 3 weeks preconception to 21 days postparturition. On postnatal day 1, pups were cross-fostered to the same or opposite dams and divided into the following four groups: CC, DD, CD, and DC (first letter: original mothers diet; second letter: nursing mothers diet). All offspring were fed a control diet beginning at weaning (day 21) and were killed on day 200±7. Serum insulin and adipokines in offspring were measured using ELISA kits. Principal Findings In males, mean levels of insulin, glucose, and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) were higher in the DD and DC groups than in the CC group. We found no difference in HOMA-IR between the CC and CD groups in either males or females. Expression of Hsd11b1 was lower in male DD rats than in CC rats. Hsd11b1 expression in male offspring nursed by cross-fostered dams was higher than that in those nursed by dams fed the same diet; CC vs. CD and DD vs. DC. In females, Hsd11b1 expression in DC rats was higher than that in CC rats. Conclusions These findings indicated that maternal Ca restriction during pregnancy and/or lactation alters postnatal growth, Hsd11b1 expression, and insulin resistance in a sex-specific manner.

A nuclear factor-κB inhibitor, dehydroxymethylepoxyquinomicin, ameliorates GVHD in allogeneic bone marrow transplantation

GVHD is a crucial mortality factor in allogeneic bone marrow transplantation (ABMT). In this paper, we show that dehydroxymethylepoxyquinomicin (DHMEQ), a novel inhibitor of nuclear factor-κB, suppresses GVHD, resulting in an improved mortality rate in a mouse ABMT model. Bone marrow cells from C57BL/6 mice (B6 mice) were transplanted into lethally irradiated BALB/c mice. Two weeks later, spleen cells from B6 mice were transplanted into the irradiated BALB/c mice. From one week after the injection of spleen cells, when the mice started to show GVHD, the mice were also injected intraperitoneally daily with DHMEQ or vehicle only (DMSO) for 4 weeks. By 80 days after the ABMT, 6/14 of the vehicle-injected mice (43%) had died because of GVHD, whereas all DHMEQ-injected mice survived this observation period and developed milder GVHD than the vehicle-injected mice. When regulatory T cells were reduced by the injection of anti-folate receptor 4 (FR4) antibody, the effects of DHMEQ were reduced. These findings suggest that administration of DHMEQ could become a new strategy for preventing fatalities from GVHD.

Oral immunotherapy combined with omalizumab for high–risk cow’s milk allergy: a randomized controlled trial

We evaluated the efficacy and safety of oral immunotherapy (OIT) combined with 24 weeks of omalizumab (OMB) at inducing desensitization in children with cow’s milk allergy (CM) compared with an untreated group. The present study was a prospective randomized controlled trial. Sixteen patients (age, 6–14 years) with high IgE levels to CM were enrolled in the present study. Patients were randomized 1:1 to receive OMB-OIT group or untreated group. The primary outcome was the induction of desensitization at 8 weeks after OMB was discontinued in OMB-OIT treated group and at 32 weeks after study entry. None of the 6 children in the untreated group developed desensitization to CM while all of the 10 children in the OIT-OMB treated group achieved desensitization (P < 0.001). A significantly decreased wheal diameter in response to a skin prick test using CM was found in the OMB-OIT treated group (P < 0.05). These data suggest that OIT combined with OMB using microwave heated CM may help to induce desensitization for children with high-risk CM allergy. This prospective randomized controlled trial was intended for 50 participants but was prematurely discontinued due to overwhelming superiority of OMB combined with microwave heated OIT over CM avoidance.

A Calcium-Deficient Diet in Rat Dams during Gestation Decreases HOMA-β% in 3 Generations of Offspring

Background: Prenatal malnutrition can affect the phenotype of offspring by altering epigenetic regulation. Calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome. Aims: We hypothesized that a Ca-deficient diet during pregnancy would alter insulin resistance and secretion in more than 1 generation of offspring. Methods: Female Wistar rats consumed either a Ca-deficient or a control diet ad libitum from 3 weeks before conception to 21 days after parturition and were mated with control males. Randomly selected F1 and F2 females were mated with males of each generation on postnatal day 70. The F1 and F2 dams were fed a control diet ad libitum during pregnancy and lactation. All offspring were fed a control diet starting at the time of weaning and were sacrificed on day 180. Results: HOMA-β% decreased in F1 through F3, and levels in F2 and F3 males and females were significantly lower than in controls. The mean levels of insulin and HOMA-IR were higher in F1 males but lower in F3 males than in control males. The HOMA-IR did not differ between any of the female offspring and controls. Conclusions: Maternal Ca restriction during pregnancy and/or lactation influences insulin secretion in 3 generations of offspring.

Soluble urokinase receptor in a toddler with focal segmental glomerulosclerosis

To the Editor: We read with great interest the article entitled ‘A multicenter cross-sectional study of circulating soluble urokinase receptor in Japanese patients with glomerular disease’ by Wada et al.1 in the latest issue. In conflict with the results by Wei et al.,2 they concluded that soluble urokinase receptor (suPAR) is not a useful parameter for differentiating focal segmental glomerulosclerosis (FSGS) from the other glomerular diseases and is inversely correlated with estimated glomerular filtration rate (eGFR) in each patient. Although it is known that renal maturation assessed by GFR occurs rapidly during the first 3 years of age, when it reaches a level equivalent to that in adults,3 both studies1, 2 do not include such toddlers with renal development. Therefore, we would like to introduce our case of a 2-year-old Japanese boy with typical FSGS whose serum suPAR levels were repeatedly measured during renal maturation. The sera were collected at either nephrotic stage (n=15) or remission stage (n=8). The suPAR levels were measured with the same kit as that used in the previous studies.1, 2 An eGFR was also calculated by a formula for Japanese children at each sampling.4 As shown in Table 1, all samples demonstrated the reference value (<3000 pg/ml (ref. 2)), and there was no significant difference in suPAR levels between nephrotic stage and remission stage.